1. Field of the Invention
The present invention relates to a method of and an apparatus for managing printing data including parts data representing pictures and photographs image reproduction data representing a one-page image used in prepress process.
2. Description of the Prior Art
A computer-aided prepress system consists of various devices, which generally include a reading scanner, an text editing device, a block-copy production apparatus, and a page make-up apparatus. Desirable printed matter is created with such devices according to the following process. Various parts data including picture data and character data are generated with the reading scanner and the text editing device. The parts data are then integrated to image reproduction data representing a one-page image with block-copy production apparatus and page make-up apparatus. Printing plates are produced from the image reproduction data, and the desired printed matter is printed with the printing plates by a printing machine. In such a prepress system, some devices have a storage unit which stores printing data in an off-line medium such as a magnetic tape or an optical disk. Printing data, or parts data, generated with a reading scanner is immediately stored in a magnetic tape of the storage unit, and the magnetic tape is successively transferred to other devices for editing, lay-out, or further processing. Namely, transfer of printing data is attained through the off-line media like magnetic tapes.
Picture image data, especially of a full-color image, has a large data volume and thereby requires a large capacity of a storage unit. For example, image data representing one full-color picture image of size A4 requires the capacity of 60 MB (Mega Bites). Any device in the printing system which treats the printing data including a picture image requires a storage unit of a large capacity, even if the device does not change the printing data itself. This results in the increased price of each device in the system and sometimes prevents desirable extension of the system.
Incidentally, in the current prepress system, an operator checks the progress of the prepress process without reading the printing data stored in a magnetic tape with a prepress device. Such direct access method is troublesome and time-consuming.
Some printing data needs to be stored for a certain time period so that they can be used in reprinting, reimpression, or partial use for other prints. Such printing data stored in magnetic tapes are classified according to a register book including names of clients and dates of prints, and held in a cabinet. Printing data required for reprinting or reimpression is retrieved manually according to the contents of the register book. This data management system is also troublesome and consumes much time for information storage and retrieval.